Method and apparatus for making composite glass



NOV. 14, 1933. J s s 1,934,772

METHOD AND APPARATUS FOR MAKING COMPOSITE GLASS Filed April 16. 1930 INVENTOR. gwfflw Q44.

Patented Nov. 14,1933} 7 ivm'rnon'ann APPARATUS FOR ,-,ooMPosITE GLASS James H;-Sherts,1Brackenridge, Pa., assignor to v 'DhplateQorporation, a corporation of Dela ware I "Application :April16, 1930. Serial No. 1;l1 ,158 4 j 4 Claims. r01. 18- -17) The invention relates toapparatusfor making composite glass, and constitutes an improvel5 pressure isapplied above theidiaphragm. Pre-- liminary tothe pressing operation, an .is exhausted from the space beneath the diaphragm in-order to withdraw any 'air which may be entrapped between the sheets. The present-im- ,20' provement is designed to increase the life of the rubber diaphragms; which" have beenifound to cut out 'rapidlyin service and tosprovidef fora more complete withdrawalofthe airifro'm between the sheets ,tobe 'compositedflpreliminary 25' to the pressing operation. xBri'efly statedythe invention consists in-theuse of arelativ'ely thin f rubber sheetwhich isplaced over the sheetsto be composited preliminary to the step of exhausting the air from between the sheets and 30 preliminary to applying the compositing pressure. The use of this additional sheet protects the diaphragm from cutting and wearingwhere it engages the corners of; the upper glass sheet of the series, and thus increases the life of [such dia- 135, phragm several times over. For the reason later explained, its use also permits'of a much more complete exhaustion of the air from betweenrthe sheets, so that air pockets injthe composited plates are avoided and thequality'of the prod- 4Q uct improved. One embodiment of the invention is shown in the accompanying drawing, wherein:

QFigure 1 is a vertical section through the apparatus inopen position. And Fig. 2 is a similar 7 view on an enlarged scale but' with the lid of the 1 A5; apparatus closed. I

Referring tothe drawing, 1 is the platen of a press similar to that shown in my application heretofore referred to; This platen constitutes the upper wall of the chamber 2for the fluid which 5.50.: heats the platen. The fiuid'is appliedfthrough the connections 3, 4 and 5 and may be steam ora liquid heated 'toa temperature sufficient for the purpose; The upper surface of. the platen is pro--.

- vided with ;a. series of grooves 6 all connected. 5-55? with the pipe 'Zby meansfof which the air maybe and. light asfcompared; with the diaphragm. 14,

exhausted from. the space above, the platen preliminary to the application of compositing pressure, as, hereinafter described. The platen'l-is. mounted in asuitable hollow framework'8 closed on the lower side by theplate'9.- i The cover of the-device comprisesaplatelfl hingedto one of the members; 8, as indicated at 11, and provided with a latch bar 12 by means of which the lid may be locked in' closed'position,

at which time the bar 12 may. be moved gbeneath Q5;

thelugs 13 carried-'bythe member 8. Secured" to the lower side of the lid is the rubber diaphragm14, the edges of such diaphragm lying between the clamping strips 15.securedin-posi'- tion by means of the screws 16. Air is supplied 7 to thespace 17' behindthe'diaphragm by means of the pipe 18-connected to asuitable source -.of supply As indicatedtin Fig. 2, the set of sheets to be composited comprises a pair of glass sheets 19, 19 and an interposed sheet 2fl'of'pyroxylin 7Q plastic, the opposing surfaces of the s heetsbeing provided with a suitable cement for sticking them together upon -the application ofheat and pres'sureas iswell known in the art. Interposed between- ;the -bottomsheet of glass 19 and the 8G platen 1 isa sheet of woven .metaljscreenf21',

preferably copper, such sheet being-somewhat greater in area than that of the sheets to be composited. The use of this sheet 21 constitutes a departure from my application heretofore re- ,5

ferred to and constitutes no part of my-invention., 7 This sheet of screen'constitutes a cushion V glass than could otherwise be. secured. Q

, Fitting over the set of sheets to be composited is a rubbersheet 22 which is relativelythin as compared to the diaphragm 14. This sheet isvery light and may be removed when the cover is raised, but is clamped in position by the cover 95 when the cover is closed, as indicatedin Fig.2. Before lowering the cover to closed position, air

is exhausted from the space between the rubber sheet 22 and the platen, the purpose being to withdraw any air which maybe entrapped'be- 1,9 tween the opposing. surfaces of the pyroxylin plastic sheet 20f and the glass sheets 'l9j, 119. Since the cover 10 of thepress is up at this time, the expulsion of the air'from between the surerator who presses down on top-of thersheet 22 abovethe sheets.19,19,"20 as the airis being-ere r hausted. Since the sheet '22 'is relatively-thin the 'te'ndent'zy of the rubbersheet to press the cuts out where it passes 'aroundthe corners of the glasssheet, but this sheet, being entirely free from the apparatus when the lid is raised, is easily replaced and its cost is slight as compared with that of the diaphragm 14. The useof the rubber diaphragm, therefore, involves a considerable economy in the'operation of the machine. After the air is exhausted frombeneath the sheet 22, air pressure is supplied behind the diaphragm 14 in order to secure the necessary compositing pressure. This pressure ismaintained for. several minutes, the sheets to be jcomposited being heated during this period from the platen v1 which is in turn heated by the steam or hot liquid which is circulated through the chamber 2. After the compositing action is completed, the air pressure behind the diaphragm is released, the locking bar 12 is moved back, and the lid-is raised, after. which the sheet 22 vis-removed, thus exposing the composited plate which can now=be removed. The

apparatus is now ready for another compositing actionp- In addition to protecting the diaphragm from the sharp edges'of the glass and the abrasion of the copper screen, the, sheet 22 performs the further functionof giving the diaphragm protection from. the heat of the platen 1 which protection is another factor tending to increasethe life of the diaphragm. The use of the sheet-22 alsopermits the operatorto see after the vacuum' is put on whether or not the plates'are. laid up properly and whether asatisfactory vacuum is applied before the lid is closed: Without this sheet, these conditions'would be obscured after the .:'closure of. the. lid, and the results secured correspondinge.

flexible sheet and the platen with the'cover in v t W 1,934,772 edges of the sheets 19, 19, 20 together and pre r vent the escape of air from the central portions 1. Apparatus formaking composite glass comprising a metal platen for supporting the sheets to be composited,-means for heating the platen, a movable metal cover fitting over the platen and provided on its inner side with a flexible diaphragm, a flexible sheet impervious to air fitting removabl y over the sheets to be: composited. which are supported on theplaten, means for exhausting .the air from the space between the open position, and means for supplying fluid under pressure behind the diaphragm.

. platen, with the. cover in open position, and means for supplying fluid' under pressure'behind the.

diaphragm.

3.. Apparatusfor making composite glass comprising a metal platen for supporting the sheets to be composited, meansfor heating. the platen,

a movablemetal cover fitting over the platen and provided on: itsinner side. with ,a:rubber.;dia

phragm, a rubber sheet whichis relatively 'thin 105.

as compared with-the diaphragm fitting removably overgthe sheets to be composited which are supported on the-platen, means for exhausting the air from the space between thev rubber sheet and the platen with the cover in open position, and means for supplying, fluid under pressure behind the diaphragm. Y

4. A method of making composite. glass which comprises superposing ,a. plurality of sheetsof glass, interposing a reinforcing material between the sheets which, is; adapted to ,be adhesively united thereto, disposing a flat sheet of flexible material impervious to air over one side of the glass, creating.a vacuum in the-space coveredby the material andapplying a compacting pressure 129 JAMES H. SI-IERTSJ.

, tolthe assembly thus formed. I 

